Laparoscopic instrument and cannula assembly and related surgical method

ABSTRACT

A laparoscopic port assembly includes a cannula unit including three cannulas each extending at an acute angle relative to a base. The cannulas are flexible for receiving respective angulated laparoscopic instruments. The cannula unit is rotatingly received in a port holder for rotation about a longitudinal axis of the holder, the holder being disposable in an opening in a patient&#39;s skin.

FIELD OF THE INVENTION

The present invention relates to surgical instruments, surgical port assemblies, and an associated method. The instruments, port assemblies and method are particularly useful in the performance of laparoscopic procedures entirely through the umbilicus.

BACKGROUND OF THE INVENTION

Abdominal laparoscopic surgery gained popularity in the late 1980's, when benefits of laparoscopic removal of the gallbladder over traditional (open) operation became evident. Reduced postoperative recovery time, markedly decreased post-operative pain and wound infection, and improved cosmetic outcome are well established benefits of laparoscopic surgery, derived mainly from the ability of laparoscopic surgeons to perform an operation utilizing smaller incisions of the body cavity wall.

Laparoscopic procedures generally involve insufflation of the abdominal cavity with CO2 gas to a pressure of around 15 mm Hg. The abdominal wall is pierced and a 5-10 mm in diameter straight tubular cannula or trocar sleeve is then inserted into the abdominal cavity. A laparoscopic telescope connected to an operating room monitor is used to visualize the operative field, and is placed through (one of) the trocar sleeve(s). Laparoscopic instruments (graspers, dissectors, scissors, retractors, etc.) are placed through two or more additional trocar sleeves for the manipulations by the surgeon and surgical assistant(s).

Recently, so-called “mini-laparoscopy” has been introduced utilizing 2-3 mm diameter straight trocar sleeves and laparoscopic instruments. When successful, mini-laparoscopy allows further reduction of abdominal wall trauma and improved cosmesis. However, instruments used for mini-laparoscopic procedures are generally more expensive and fragile. Because of their performance limitations, due to their smaller diameter (weak suction-irrigation system, poor durability, decreased video quality), mini-laparoscopic instruments can generally be used only on selected patients with favorable anatomy (thin cavity wall, few adhesions, minimal inflammation, etc.). These patients represent a small percentage of patients requiring laparoscopic procedure. In addition, smaller, 2-3 mm, incisions may still cause undesirable cosmetic outcomes and wound complications (bleeding, infection, pain, keloid formation, etc.).

Since the benefits of smaller and fewer body cavity incisions are proven, it would be attractive to perform an operation utilizing only a single incision in the navel. An umbilicus is the thinnest and least vascularized, and a well-hidden, area of the abdominal wall. The umbilicus is generally a preferred choice of abdominal cavity entry in laparoscopic procedures. An umbilical incision can be easily enlarged (in order to eviscerate a larger specimen) without significantly compromising cosmesis and without increasing the chances of wound complications. The placement of two or more standard (straight) cannulas and laparoscopic instruments in the umbilicus, next to each other, creates a so-called “chopstick” effect, which describes interference between the surgeon's hands, between the surgeon's hands and the instruments, and between the instruments. This interference greatly reduces the surgeon's ability to perform a described procedure.

Thus, there is a need for instruments and trocar systems, which allow laparoscopic procedures to be performed entirely through the umbilicus while at the same time reducing or eliminating the “chopstick effect”. A laparoscopic procedure performed entirely through the umbilicus, using the laparoscopic instruments and trocar system according to an embodiment of the present invention, allows one to accomplish the necessary diagnostic and therapeutic tasks while further minimizing abdominal wall trauma and improving cosmesis.

OBJECTS OF THE INVENTION

The present invention provides instruments and cannula or port assemblies for the performance of surgical procedures, particularly including laparoscopic procedures, for instance, entirely through the umbilicus.

An object of the present invention is to provide an improved port assembly for facilitating access to internal organs of a patient during laproscopic procedures.

Another object of the present invention is to provide such a port assembly that provides enlarged workspace for the hands of the surgeon(s) when plural laparoscopic instruments are placed through the umbilicus.

An additional object of the present invention is to provide improved laparoscopic instruments for facilitating operations through the umbilicus.

These and other objects of the invention will be apparent from the drawings and descriptions herein. Although each object of the invention is believed to be attained by at least one embodiment of the invention, there is not necessarily any single embodiment that achieves all of the objects of the invention.

SUMMARY OF THE INVENTION

The present invention facilitates the performance of laparoscopic surgical procedures wherein several laparoscopic instruments are inserted into a patient through respective cannulas all extending through the same opening in the patient, for instance, through the umbilicus. The advantages of such an operation include minimizing trauma to the patient and accelerating the patient recovery.

A surgical port assembly that facilitates the performance of such a laparoscopic surgical procedure comprises, in accordance with the present invention, a cannula unit including at least one cannula member, and a holder disposable in an opening in a patient's skin for receiving the cannula component so that the cannula component is movable relative to the holder during a surgical procedure. Preferably, the cannula unit is rotatable with respect to the holder about a longitudinal axis of the holder. It is contemplated that the holder is fastened to the patient during the surgical operation, so that the cannula unit is movable relative to the patient.

Pursuant to another feature of the present invention, the cannula unit comprises a base or frame that is removably attachable to the holder and that defines a closure surface extending, during the surgical procedure, substantially tangentially to the patient's skin at the opening. The cannula member is connected to the base and defines an access path through the closure surface. The cannula member extends at an acute angle relative to the closure surface so that the cannula is inclined relative to the patient's skin surface during the surgical procedure.

Pursuant to further features of the present invention, the cannula is flexible and has a relaxed configuration that is linear. The base or frame is provided with a panel or wall forming the closure surface.

In a particular embodiment of the present invention, the cannula is one of a plurality of cannulas each extending at an acute angle relative to the closure surface so that the cannulas are all inclined relative to the patient's skin surface during the surgical procedure.

Pursuant to additional features of the present invention, the cannula unit is partially insertable into the holder, while the port assembly further comprises a connector member for removably attaching the cannula unit to the holder, the connector also being partially insertable into the holder.

The holder and the connector member may be provided with cooperating locking elements such as projections and slots for reversibly securing the cannula unit to the holder. Thus, after placement of the holder in an opening in the patient (and after removal of an insert assist member from the holder), the base or frame of the cannula unit is inserted into the holder and secured thereto by an insertion and a rotation of the connector so that the projections and slots are interlocked.

The base or frame of the cannula unit may include a frustoconical portion insertable into the holder. Similarly, the connector may include a frustoconical portion insertable into the holder to secure the cannula unit to the holder. The holder is provided internally with a shoulder engaging a lower end of the cannula unit.

As indicated above, in one embodiment of the present invention, a surgical port assembly comprises (a) a base or frame seatable in an opening in a patient's skin and defining a closure surface extending substantially tangentially to the patient's skin at the opening during a surgical procedure and (b) a cannula connected to the base and defining an access path through the closure surface. The cannula extends at an acute angle relative to the closure surface so that the cannula is inclined relative to the patient's skin surface during the surgical procedure. The cannula may be one of a plurality of cannulas each extending at an acute angle relative to the closure surface so that the cannulas are all inclined relative to the patient's skin surface during the laparoscopic procedure.

Where the closure surface is located in a main plane, the cannulas have linear configurations, and the base or frame has a longitudinal axis, each of the cannulas may define a respective secondary plane oriented perpendicularly to the main plane, each the secondary plane being spaced from the longitudinal axis. The cannulas may be three in number with the secondary planes disposed at angles of 120° relative to each other.

A surgical method in accordance with the present invention comprises forming an opening in a patient, inserting a cannula holder through the opening, disposing a plurality of cannulas in the holder so that after inserting of the holder the cannulas traverse the holder and extend from outside the patient to inside the patient, thereafter inserting a plurality of elongate medical instruments through the respective cannulas, and rotating the cannulas and the instruments relative to the holder, about a longitudinal axis of the holder.

In accordance with another aspect of the present invention, where the cannulas are attached to a base member, the disposing of the cannulas in the holder includes inserting the base member into the holder, the base member being in rotatable engagement with the holder. The disposing of the cannulas in the holder may further include attaching a locking member to the holder to maintain the base member in rotatable engagement with the holder.

A laparoscopic medical instrument insertable through a laparoscopic trocar sleeve comprises, in accordance with the present invention, an elongate shaft, an operative tip disposed at one end of the shaft, and a first actuator disposed at an opposite end of the shaft. The actuator is operatively connected to the operative tip via the shaft for controlling the operation of the operative tip. The shaft has a straight proximal end portion, a curved middle portion and a straight distal end portion, the distal end portion extending at an angle with respect to the proximal end portion. The proximal end portion is provided with a first rotary joint so that the distal end portion and the operative tip are rotatable about a longitudinal axis of the proximal end portion. The distal end portion is provided with a second rotary joint so that the operative tip is rotatable about a longitudinal axis of the distal end portion. A second actuator disposed at the end of the shaft opposite the operative tip is operatively connected to the proximal end portion of the instrument shaft for rotating the distal end portion thereof and the operative tip about the longitudinal axis of the proximal end portion of the shaft. A third actuator disposed at the end of the shaft opposite the operative tip is operatively connected to the distal end portion of the shaft for rotating the operative tip about the longitudinal axis of the distal end portion.

The proximal end portion, the middle portion and the distal end portion of the instrument shaft are each substantially rigid throughout so that they cannot be bent. In one embodiment of the invention, the instrument shaft has a hockey-stick shape. Two laparoscopic surgical instruments each having a hockey stick shape are advantageously used in a crossed configuration, which markedly improves the degrees of freedom of the instruments, particularly during lateral (medial-lateral) movements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a laparoscopic port having multiple cannulas, in accordance with the present invention.

FIG. 2 is a cross-sectional view of the laparoscopic port or cannula assembly of FIG. 1, taken along line II-II in FIG. 3.

FIG. 3 is a top view of the laparoscopic port or cannula assembly of FIG. 1.

FIG. 4 is a perspective view of an annular holder disposable in an opening in a patient for receiving the laparoscopic port or cannula assembly of FIGS. 1-3.

FIG. 5 is a top plan view of the port holder of FIG. 4.

FIG. 6 is a longitudinal cross-sectional view of the port holder of FIGS. 4 and 5, taken along line VI-VI in FIG. 5.

FIG. 7 is another longitudinal cross-sectional view of the port holder of FIGS. 4 and 5, taken along line VII-VII in FIG. 5.

FIG. 8 is a perspective view of the laparoscopic port or cannula assembly of FIGS. 1-3, together with the port holder of FIGS. 4-7, showing the laparoscopic port or cannula assembly inserted into and attached to the port holder.

FIG. 9 is a top plan view of the laparoscopic port or cannula assembly of FIGS. 1-3 connected to the port holder of FIGS. 4-7, as shown in FIG. 8.

FIG. 10 is a longitudinal cross-sectional view taken along line X-X in FIG. 9.

FIG. 11 is a perspective view of a cannula with an insufflation valve, included in the laparoscopic port or cannula assembly of FIGS. 1-3 and 8-10.

FIG. 12 is a side elevational view of the cannula of FIG. 11, on a larger scale.

FIG. 13 is a longitudinal cross-sectional view of the cannula of FIGS. 11 and 12, taken along line XIII-XIII in FIG. 12.

FIG. 14 is a transverse cross-sectional view of the cannula of FIGS. 11 and 12, taken along line XIV-XIV in FIG. 12.

FIG. 15 is a perspective view of a cannula without an insufflation valve, included in the laparoscopic port or cannula assembly of FIGS. 1-3 and 8-10.

FIG. 16 is a side elevational view of the cannula of FIG. 16, on a larger scale.

FIG. 17 is a longitudinal cross-sectional view of the cannula of FIGS. 15 and 16, taken along line XVII-XVII in FIG. 16.

FIG. 18 is a transverse cross-sectional view of the cannula of FIGS. 15 and 16, taken along line XVIII-XVIII in FIG. 16.

FIG. 19 is a perspective view of an insertion plug used to facilitate insertion of the port holder of FIGS. 4-7 in a patient at the beginning of a laparoscopic procedure.

FIG. 20 is a top perspective view of the insertion plug of FIG. 19 temporarily inserted in and attached to the port holder of FIGS. 4-7.

FIG. 21 is a top plan view of the assembled insertion plug and port holder of FIG. 20.

FIG. 22 is a longitudinal cross-section taken along line XXII-XXII in FIG. 21.

FIG. 23 is a bottom perspective view of the assembled insertion plug and port holder of FIGS. 20-22.

FIG. 24 is a side elevational view of a laparoscopic instrument utilizable with the multiple-cannula port assembly of FIGS. 8-10, in accordance with the present invention.

FIG. 25 is a top plan view of the laparoscopic instrument of FIG. 24.

FIG. 26 is partially a side elevational view and partially a cross-sectional view taken along line XXVI-XXVI in FIG. 25.

FIG. 27 is a partial longitudinal cross-sectional view also taken along line XXVI-XXVI in FIG. 25.

FIG. 28 is a longitudinal cross-sectional view, on a larger scale, of a distal end of the laparoscopic instrument of FIGS. 24-27.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As depicted in FIGS. 1-3, a laparoscopic port or cannula assembly 100 comprises a cannula unit 102 and a connector 104 associated therewith for removably fastening the cannula unit to an annular port holder 106 (FIGS. 4-8 and 10) that is disposed in an opening (e.g., formed in the umbilicus) in a patient. Cannula unit 102 is coupled to port holder 106 by connector 104 so as to permit rotation of cannula unit 102 about a longitudinal axis 108 (FIGS. 7 and 10) of holder 106.

Cannula unit 102 comprises a base or frame 110 that is insertable into and removably attachable to port holder 106. Base or frame 110 includes a planar panel or wall 112 defining a closure surface or plane SC extending, during a laparoscopic surgical procedure, substantially tangentially to the patient's skin at the opening through with port holder 106 extends. Base or frame 110 further includes a seating ring 114 and a sealing ring 116.

Cannula unit 102 additionally comprises three cannula members 118, 120, 122 each connected to base or frame 110 and defining a respective access path through closure surface SC. Cannula members 118, 120, 122 each extend at an acute angle relative to closure surface SC so that the cannulas are inclined relative to the patient's skin surface during a laparoscopic surgical procedure. Cannula members 118, 120, 122 include flexible tubular portions 124, 126, 128 that have linear configurations in a relaxed or unstressed condition.

Each cannula member 118, 120, 122 defines a respective plane P1, P2, P3 (FIG. 3) oriented perpendicularly to closure surface or plane CS (the main plane) and spaced from a longitudinal axis 130 of base or frame 110. These secondary planes P1, P2, and P3 are disposed at angles of 120° relative to each other, as indicated in FIG. 3. Connector 104 is loosely coupled to cannula unit 102 so as to be freely movable along axis 130 of the cannula unit, between base 110 and valve components of cannulas 118, 120, 122.

Connector 104 includes a frustoconical portion 132 insertable into port holder 106 (see FIG. 10) and further includes a pair of flanges 134, 136 for temporarily locking cannula unit 102 to holder 106. To that end, flanges 134, 136 are provided with dual-lobed slots 138, 140 for receiving respective pins or projections 142, 144 on port holder 106 (see FIGS. 4, 5, 7, 8, 9). Flanges 134 and 136 are also provided with respective pairs of upturned ears 146 and 148 functioning in part as thumb and finger rests for swiveling connector 104 about axis 108 (and 130) to reversibly secure connector 106 and concomitantly cannula unit 102 to port holder 106.

As illustrated in FIGS. 4-7, port holder 106 includes a tapered, slightly frustoconical sleeve 150 provided along an outer surface with a pair of annular beads or ribs 152 and 154 and along an inner surface with a shoulder 156 that serves as an abutment or rest for seating ring 114 of cannula unit 102. At a wider end of sleeve 150, holder 106 includes a pair of diametrically opposed flanges 158, 160 and a pair of diametrically opposed ears 162, 164. Pins or projections 142, 144 are rigid with flanges 158, 160, while ears 162, 164 carry respective flat-headed posts 166, 168 around which sutures are wound to fasten holder 106 to the skin of the patient. Rubber gaskets 167 and 169 may be provided for clamping suture threads to posts 166 and 168. Alternatively or additionally, sutures anchoring port holder 106 to the body wall of the patient may be inserted through slots 163 a, 163 b and 165 a, 165 b and partially wrapped around bases 171 and 173 of ears 162, 164 (see FIG. 5).

After placement of holder 106 in an opening in the patient (and after removal of an insert assist member 170, FIGS. 19-22, from the holder), base or frame 110 of cannula unit 102 is inserted into holder 106 until seating ring 114 engages shoulder 15 (see FIG. 10). Cannula unit 110 is secured to holder 106 by an insertion and a subsequent rotation of connector 104 relative to holder 106, as indicated by an arrow 172 in FIGS. 8 and 9, so that projections 142, 144 and slots 138, 140 are interlocked (see FIGS. 8-10). After this locking of connector 104 to holder 106, cannula unit 102 is rotatable about axes 108 and 130 in opposition to a frictional drag force exerted by virtue of sealing ring 116.

As illustrated in FIGS. 11-14, cannula unit 118 includes valve component 174 connected to tubular portion 124. Valve component 124 includes an insufflation port 175 for receiving a tube (not shown) for guiding carbon dioxide gas from a pressurized source into the patient. As shown particularly in FIG. 13, valve component 124 of cannula member 118 includes a valve box or casing 176 with a cover or closure 178 to which an extension tube 180 is attached. At an end opposite valve casing 176, extension tube 180 is provided with a sleeve 182, a valve seal 184, a disc 185, and a cap 186. Valve component 174 further includes a valve door 188 that is biased into a closure position shown in FIG. 13 by a helical or coil spring 190. Door 188 is supported by a mounting bracket and associated hardware 191. An O-ring seal 192 is provided for inhibiting the escape of insufflation gas from a patient through extension tube 124 when a laparoscopic surgical instrument does not traverse cannula member 118.

As illustrated in FIGS. 1-3 and 8-10, cannula members 120 and 122 include respective valve components 194 and 196 connected to respective flexible tubular portions 126 and 128. These valve components are structurally identical, a representative component 194 being depicted in FIGS. 15-18. Valve component 194 includes a valve box or casing 198 with a cover or closure 200 to which an extension tube 202 is attached. At an end opposite valve casing 198, extension tube 202 is provided with a sleeve 204, a valve seal 206, a disc 208, and a cap 210. Valve component 194 further includes a valve door 212 that is biased into a closure position shown in FIG. 17 by a helical or coil spring 214. Door 212 is supported by a mounting bracket and associated hardware 216. An O-ring seal 218 is provided for inhibiting the escape of insufflation gas from a patient through extension tube 202 when a laparoscopic surgical instrument does not traverse the respective cannula member 120 (or 122).

As shown in FIG. 19, insert assist member 170 includes a rounded conical tip 220, a cylindrical middle portion 222 and a slightly tapered or frustoconical outer portion 224. Outer portion 224 is provided with a pair of flanges 226, 228 for temporarily locking insert assist member 170 to port holder 106. To that end, flanges 226, 228 are provided with dual-lobed slots 230, 232 for receiving respective pins or projections 142, 144 on port holder 106, as depicted in FIGS. 20-22. Flanges 226 and 228 are formed with respective pairs of upturned ears 234 and 236 that are manually engageable by a user to reversibly secure connector insert assist member 170 to port holder 106.

After a small incision or opening is made in a patient, port holder 106 with insert assist member 170 connected thereto is inserted through the incision. Sutures (not shown) are stitched to the patient and are wound around and tied to posts 166, 168 to firmly secure the port holder 106 to the patient. Insert assist member 170 is then removed, by a reverse rotation unlocking flanges 226, 228 from pins or projections 142, 144 and by separating the inset assist member from holder 106. Cannula unit 102 is then attached to holder 106 as described above.

FIGS. 24-29 depict a laparoscopic surgical instrument 238 insertable through a laparocopic trocar sleeve or cannula such as cannula member 118, 120, or 122 of the port assembly of FIGS. 1-3 and 8-10 for executing a laparoscopic surgical operation. Instrument 238 comprises an elongate shaft 240, an operative tip 242 disposed at one end of the shaft, and a hand-grip-type actuator 244 disposed at an opposite end of the shaft. Actuator 244 is operatively connected to operative tip 242 via shaft 240 for controlling the operation of the operative tip.

Shaft 240 has a straight proximal end portion 246, a curved middle portion 248 and a straight distal end portion 250, the distal end portion extending at a non-zero angle with respect to the proximal end portion, as shown in FIGS. 24, 26 and 27. Proximal end portion 246 is provided with a first rotary joint 252 so that distal end portion 250 and operative tip 242 are rotatable about a longitudinal axis 254 of proximal end portion 246. Distal end portion 250 is provided with a second rotary joint 256 so that operative tip 242 is rotatable about a longitudinal axis 258 of the distal end portion. A rotary actuator or knob 260 disposed at the proximal end of instrument 238 is operatively connected to proximal end portion 246 of instrument 240 for rotating distal end portion 250 and operative tip 242 about longitudinal axis 254. Another rotary actuator or knob 262 disposed at the proximal end of instrument 238 is operatively connected to distal end portion 250 of shaft 240 for rotating operative tip 242 about longitudinal axis 258.

Proximal end portion 246, middle portion 248 and distal end portion 250 of instrument shaft 240 are each substantially rigid throughout and can only be rotated about joints 252 and 256 and not bent. The angle between axes 254 and 258 are such that shaft 240 has a shape reminiscent of a hockey stick. In an alternative embodiment of instrument 238, middle portion 248 of shaft 240 may be flexible to permit shaft 240 to alternately assume a linear configuration and the hockey-stick configuration of FIGS. 24 and 26. In that case, a handle assembly 274 is provided with an actuator (not shown) for enabling a bending of middle portion 248.

As shown in FIGS. 24-26, instrument 238 may be provided with further actuators, such as a slidable toggle switch 264, for example for performing a locking function or inducing a pivoting of operative tip 242 about an axis perpendicular to axis 258.

Actuator 244 includes a hand grip member 266 fixed relative to shaft 240 and further includes a pivotable hand grip 268. A proximal end 270 of shaft 240 is journaled in a bearing 272 about which rotary knob 262. Actuator 244, rotary knobs 260 and 262, and toggle switch 264 are parts of a handle assembly 274 also incorporating yokes 276 and 278, a stopper pin 278, a set screw 280.

FIG. 27 illustrates further parts of a shaft assembly 282 including shaft 240, a slider member 283, a socket set screw 284, an outer bearing 286, a motion bar 288, a bend tube 290, a ring 292, and an O-ring seal 294.

Rotary joint 256 is representative of joint 254 and comprises, as shown in FIG. 27, a proximal pin or inner shaft portion 296, a distal pin or inner shaft portion 298, a pair of coupling elements 300 and 302, and a transverse connector pin 304.

As illustrated in FIGS. 28 and 29, operative tip 242 exemplarily includes a pair of jaws 306 and 308 pivotably connected to a distal end of distal end portion 250 via a pivot pin 310. Jaws 306 and 308 are rotatable about pin 310 through the action of levers or arms 312, 314 that pivot in response to a longitudinal motion of a tip rod 316.

After a deployment of cannula unit 102 in a patient as described above, opeative tip 242 and shaft 240 of instrument 238 are insertable through a cannula member 118, 120, or 122, with the respective tubular portion 124, 126, or 128 bending to accommodate the bent shaft 240. The bent shape of shaft 240, as well as the rotary joints 252 and 256 facilitate the performance of laparoscopic surgical procedure using multiple laparoscopic instruments extending through a single opening in a patient, for instance, in the umbilicus. Such a procedure involves the rotation of distal end portion 250 and operative tip 242 together about axis 254 and the rotation of operative tip about axis 258. In addition, the entire instrument assembly including cannula unit 102 and multiple instruments 238 can be rotated about collinear axes 108 and 130, to optimize the simultaneous or successive access of multiple operative tips 242 to a surgical site inside a patient.

Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof. 

1. A surgical port assembly comprising: an annular holder disposable in an opening in a patient; and a cannula unit removably attachable to said holder so that said cannula unit is rotatable with respect to said holder about a longitudinal axis of said holder.
 2. The port assembly defined in claim 1 wherein said cannula unit comprises: a base removably attachable to said holder and defining a closure surface extending substantially tangentially to the patient's skin at said opening during a surgical procedure; and a cannula connected to said base and defining an access path through said closure surface, said cannula extending at an acute angle relative to said closure surface so that said cannula is inclined relative to the patient's skin surface at least in a relaxed or rest configuration of the port assembly.
 3. The port assembly defined in claim 2 wherein said cannula is flexible.
 4. The port assembly defined in claim 3 wherein said cannula has a relaxed configuration that is linear.
 5. The port assembly defined in claim 4 wherein said base is provided with a panel or wall forming said closure surface.
 6. The port assembly defined in claim 2 wherein said cannula is one of a plurality of cannulas each extending at an acute angle relative to said closure surface so that the cannulas are all inclined relative to the patient's skin surface at least in a relaxed or rest configuration of the port assembly.
 7. The port assembly defined in claim 1 wherein said cannula unit is partially insertable into said holder.
 8. The port assembly defined in claim 7, further comprising a connector member for removably attaching said cannula unit to said holder, said connector also being partially insertable into said holder.
 9. The port assembly defined in claim 8 wherein said holder and said connector member are provided with cooperating locking elements.
 10. The port assembly defined in claim 9 wherein said locking elements include projections on one of said holder and said connector member and further include slots on the other of said holder and said connector member.
 11. The port assembly defined in claim 8 wherein said cannula unit includes a base insertable into said holder and wherein said connector includes a portion insertable into said holder to secure said cannula unit to said holder.
 12. The port assembly defined in claim 7 said holder is provided internally with a shoulder engaging a lower end of said cannula unit.
 13. The port assembly defined in claim 1 wherein said holder is provided with means for releasably securing said base member to the patient.
 14. The port assembly defined in claim 1 wherein said cannula unit includes a plurality of cannula members defining respective access paths for surgical instruments.
 15. (canceled)
 16. (canceled)
 17. (canceled)
 18. A surgical port assembly comprising: a base seatable in an opening in a patient's skin, said base defining a closure surface, said closure surface extending substantially tangentially to the patient's skin at said opening during a surgical procedure; and a cannula connected to said base and defining an access path through said closure surface, said cannula extending at an acute angle relative to said closure surface so that said cannula is inclined relative to the patient's skin surface at least in a relaxed or rest configuration of the port assembly.
 19. The port assembly defined in claim 18 wherein said cannula is one of a plurality of cannulas each extending at an acute angle relative to said closure surface so that the cannulas are all inclined relative to the patient's skin surface at least in a relaxed or rest configuration of the port assembly.
 20. The port assembly defined in claim 19 wherein closure surface is located in a main plane and said cannulas have linear configurations, each of said cannulas defining a respective secondary plane perpendicular to said main plane, said base having a longitudinal axis, each said secondary plane being spaced from said longitudinal axis.
 21. The port assembly defined in claim 20 wherein said cannulas are three in number and said secondary planes are disposed at angles of 120° relative to each other.
 22. The port assembly defined in claim 18 wherein said cannula is flexible.
 23. The port assembly defined in claim 22 wherein said cannula has a relaxed or unstressed configuration that is linear.
 24. The port assembly defined in claim 18 wherein said base is provided with a panel or wall forming said closure surface.
 25. The port assembly defined in claim 18, further comprising a connector element for removably attaching said base and said cannula to a holder so that said base and cannula are movably secured to said holder, wherein said holder is seatable in an opening in a patient during a surgical procedure.
 26. A surgical port assembly comprising: a base seatable in an opening in a patient; and a plurality of separate cannula members connected to said base and defining respective access paths through the opening in the patient, said cannula members being oriented at angles relative to one another and to said base in a relaxed or rest configuration of the port assembly.
 27. The port assembly defined in claim 26 wherein said cannula members are three in number and oriented at angles of 120° with respect to each other.
 28. The port assembly defined in claim 26, further comprising a connector element for removably attaching said base with said cannula members to a holder so that said base and cannula are movably secured to said holder, wherein said holder is seatable in an opening in a patient during a surgical procedure.
 29. A surgical method comprising: forming an opening in a patient; inserting a cannula holder through said opening; disposing a plurality of cannulas in said holder so that after inserting of said holder said cannulas traverse said holder and extend from outside the patient to inside the patient; after inserting of said holder through said opening, inserting a plurality of elongate medical instruments through respective ones of said cannulas; and rotating said cannulas and said instruments relative to said holder, about a longitudinal axis of said holder.
 30. The method defined in claim 29 wherein said cannulas are attached to a base member, the disposing of said cannulas in said holder including inserting said base member into said holder, said base member being in rotatable engagement with said holder.
 31. The method defined in claim 30 wherein the disposing of said cannulas in said holder further includes attaching a locking member to said holder to maintain said base member in rotatable engagement with said holder.
 32. A laparoscopic medical instrument insertable through a laparoscopic trocar sleeve, said instrument comprising: an elongate shaft; an operative tip disposed at one end of said shaft; a first actuator disposed at an opposite end of said shaft, said actuator being operatively connected to said operative tip via said shaft for controlling the operation of said operative tip, said shaft having a straight proximal end portion, a curved middle portion and a straight distal end portion, said distal end portion extending at an angle with respect to said proximal end portion, said proximal end portion being provided with a first rotary joint so that said distal end portion and said operative tip are rotatable about a longitudinal axis of said proximal end portion, said distal end portion being provided with a second rotary joint so that said operative tip is rotatable about a longitudinal axis of said distal end portion, a second actuator disposed at said opposite end of said shaft and operatively connected to said proximal end portion for rotating said distal end portion and said operative tip about the longitudinal axis of said proximal end portion, a third actuator disposed at said opposite end of said shaft and operatively connected to said distal end portion for rotating said operative tip about the longitudinal axis of said distal end portion.
 33. The instrument defined in claim 32 wherein said proximal end portion, said middle portion and said distal end portion are each substantially rigid throughout.
 34. The instrument defined in claim 32 wherein said proximal end portion, said middle portion and said distal end portion together form a hockey-stick shape. 